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1 /* audit -- definition of audit_context structure and supporting types
2  *
3  * Copyright 2003-2004 Red Hat, Inc.
4  * Copyright 2005 Hewlett-Packard Development Company, L.P.
5  * Copyright 2005 IBM Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21 
22 #include <linux/fs.h>
23 #include <linux/audit.h>
24 #include <linux/skbuff.h>
25 #include <uapi/linux/mqueue.h>
26 
27 /* 0 = no checking
28    1 = put_count checking
29    2 = verbose put_count checking
30 */
31 #define AUDIT_DEBUG 0
32 
33 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
34  * for saving names from getname().  If we get more names we will allocate
35  * a name dynamically and also add those to the list anchored by names_list. */
36 #define AUDIT_NAMES	5
37 
38 /* At task start time, the audit_state is set in the audit_context using
39    a per-task filter.  At syscall entry, the audit_state is augmented by
40    the syscall filter. */
41 enum audit_state {
42 	AUDIT_DISABLED,		/* Do not create per-task audit_context.
43 				 * No syscall-specific audit records can
44 				 * be generated. */
45 	AUDIT_BUILD_CONTEXT,	/* Create the per-task audit_context,
46 				 * and fill it in at syscall
47 				 * entry time.  This makes a full
48 				 * syscall record available if some
49 				 * other part of the kernel decides it
50 				 * should be recorded. */
51 	AUDIT_RECORD_CONTEXT	/* Create the per-task audit_context,
52 				 * always fill it in at syscall entry
53 				 * time, and always write out the audit
54 				 * record at syscall exit time.  */
55 };
56 
57 /* Rule lists */
58 struct audit_watch;
59 struct audit_tree;
60 struct audit_chunk;
61 
62 struct audit_entry {
63 	struct list_head	list;
64 	struct rcu_head		rcu;
65 	struct audit_krule	rule;
66 };
67 
68 struct audit_cap_data {
69 	kernel_cap_t		permitted;
70 	kernel_cap_t		inheritable;
71 	union {
72 		unsigned int	fE;		/* effective bit of file cap */
73 		kernel_cap_t	effective;	/* effective set of process */
74 	};
75 };
76 
77 /* When fs/namei.c:getname() is called, we store the pointer in name and
78  * we don't let putname() free it (instead we free all of the saved
79  * pointers at syscall exit time).
80  *
81  * Further, in fs/namei.c:path_lookup() we store the inode and device.
82  */
83 struct audit_names {
84 	struct list_head	list;		/* audit_context->names_list */
85 
86 	struct filename		*name;
87 	int			name_len;	/* number of chars to log */
88 	bool			name_put;	/* call __putname()? */
89 
90 	unsigned long		ino;
91 	dev_t			dev;
92 	umode_t			mode;
93 	kuid_t			uid;
94 	kgid_t			gid;
95 	dev_t			rdev;
96 	u32			osid;
97 	struct audit_cap_data	fcap;
98 	unsigned int		fcap_ver;
99 	unsigned char		type;		/* record type */
100 	/*
101 	 * This was an allocated audit_names and not from the array of
102 	 * names allocated in the task audit context.  Thus this name
103 	 * should be freed on syscall exit.
104 	 */
105 	bool			should_free;
106 };
107 
108 /* The per-task audit context. */
109 struct audit_context {
110 	int		    dummy;	/* must be the first element */
111 	int		    in_syscall;	/* 1 if task is in a syscall */
112 	enum audit_state    state, current_state;
113 	unsigned int	    serial;     /* serial number for record */
114 	int		    major;      /* syscall number */
115 	struct timespec	    ctime;      /* time of syscall entry */
116 	unsigned long	    argv[4];    /* syscall arguments */
117 	long		    return_code;/* syscall return code */
118 	u64		    prio;
119 	int		    return_valid; /* return code is valid */
120 	/*
121 	 * The names_list is the list of all audit_names collected during this
122 	 * syscall.  The first AUDIT_NAMES entries in the names_list will
123 	 * actually be from the preallocated_names array for performance
124 	 * reasons.  Except during allocation they should never be referenced
125 	 * through the preallocated_names array and should only be found/used
126 	 * by running the names_list.
127 	 */
128 	struct audit_names  preallocated_names[AUDIT_NAMES];
129 	int		    name_count; /* total records in names_list */
130 	struct list_head    names_list;	/* struct audit_names->list anchor */
131 	char		    *filterkey;	/* key for rule that triggered record */
132 	struct path	    pwd;
133 	struct audit_aux_data *aux;
134 	struct audit_aux_data *aux_pids;
135 	struct sockaddr_storage *sockaddr;
136 	size_t sockaddr_len;
137 				/* Save things to print about task_struct */
138 	pid_t		    pid, ppid;
139 	kuid_t		    uid, euid, suid, fsuid;
140 	kgid_t		    gid, egid, sgid, fsgid;
141 	unsigned long	    personality;
142 	int		    arch;
143 
144 	pid_t		    target_pid;
145 	kuid_t		    target_auid;
146 	kuid_t		    target_uid;
147 	unsigned int	    target_sessionid;
148 	u32		    target_sid;
149 	char		    target_comm[TASK_COMM_LEN];
150 
151 	struct audit_tree_refs *trees, *first_trees;
152 	struct list_head killed_trees;
153 	int tree_count;
154 
155 	int type;
156 	union {
157 		struct {
158 			int nargs;
159 			long args[6];
160 		} socketcall;
161 		struct {
162 			kuid_t			uid;
163 			kgid_t			gid;
164 			umode_t			mode;
165 			u32			osid;
166 			int			has_perm;
167 			uid_t			perm_uid;
168 			gid_t			perm_gid;
169 			umode_t			perm_mode;
170 			unsigned long		qbytes;
171 		} ipc;
172 		struct {
173 			mqd_t			mqdes;
174 			struct mq_attr		mqstat;
175 		} mq_getsetattr;
176 		struct {
177 			mqd_t			mqdes;
178 			int			sigev_signo;
179 		} mq_notify;
180 		struct {
181 			mqd_t			mqdes;
182 			size_t			msg_len;
183 			unsigned int		msg_prio;
184 			struct timespec		abs_timeout;
185 		} mq_sendrecv;
186 		struct {
187 			int			oflag;
188 			umode_t			mode;
189 			struct mq_attr		attr;
190 		} mq_open;
191 		struct {
192 			pid_t			pid;
193 			struct audit_cap_data	cap;
194 		} capset;
195 		struct {
196 			int			fd;
197 			int			flags;
198 		} mmap;
199 	};
200 	int fds[2];
201 
202 #if AUDIT_DEBUG
203 	int		    put_count;
204 	int		    ino_count;
205 #endif
206 };
207 
208 extern int audit_ever_enabled;
209 
210 extern void audit_copy_inode(struct audit_names *name,
211 			     const struct dentry *dentry,
212 			     const struct inode *inode);
213 extern void audit_log_cap(struct audit_buffer *ab, char *prefix,
214 			  kernel_cap_t *cap);
215 extern void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name);
216 extern void audit_log_name(struct audit_context *context,
217 			   struct audit_names *n, struct path *path,
218 			   int record_num, int *call_panic);
219 
220 extern int audit_pid;
221 
222 #define AUDIT_INODE_BUCKETS	32
223 extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
224 
audit_hash_ino(u32 ino)225 static inline int audit_hash_ino(u32 ino)
226 {
227 	return (ino & (AUDIT_INODE_BUCKETS-1));
228 }
229 
230 /* Indicates that audit should log the full pathname. */
231 #define AUDIT_NAME_FULL -1
232 
233 extern int audit_match_class(int class, unsigned syscall);
234 extern int audit_comparator(const u32 left, const u32 op, const u32 right);
235 extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
236 extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
237 extern int parent_len(const char *path);
238 extern int audit_compare_dname_path(const char *dname, const char *path, int plen);
239 extern struct sk_buff *	    audit_make_reply(int pid, int seq, int type,
240 					     int done, int multi,
241 					     const void *payload, int size);
242 extern void		    audit_panic(const char *message);
243 
244 struct audit_netlink_list {
245 	int pid;
246 	struct sk_buff_head q;
247 };
248 
249 int audit_send_list(void *);
250 
251 extern int selinux_audit_rule_update(void);
252 
253 extern struct mutex audit_filter_mutex;
254 extern void audit_free_rule_rcu(struct rcu_head *);
255 extern struct list_head audit_filter_list[];
256 
257 extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);
258 
259 /* audit watch functions */
260 #ifdef CONFIG_AUDIT_WATCH
261 extern void audit_put_watch(struct audit_watch *watch);
262 extern void audit_get_watch(struct audit_watch *watch);
263 extern int audit_to_watch(struct audit_krule *krule, char *path, int len, u32 op);
264 extern int audit_add_watch(struct audit_krule *krule, struct list_head **list);
265 extern void audit_remove_watch_rule(struct audit_krule *krule);
266 extern char *audit_watch_path(struct audit_watch *watch);
267 extern int audit_watch_compare(struct audit_watch *watch, unsigned long ino, dev_t dev);
268 #else
269 #define audit_put_watch(w) {}
270 #define audit_get_watch(w) {}
271 #define audit_to_watch(k, p, l, o) (-EINVAL)
272 #define audit_add_watch(k, l) (-EINVAL)
273 #define audit_remove_watch_rule(k) BUG()
274 #define audit_watch_path(w) ""
275 #define audit_watch_compare(w, i, d) 0
276 
277 #endif /* CONFIG_AUDIT_WATCH */
278 
279 #ifdef CONFIG_AUDIT_TREE
280 extern struct audit_chunk *audit_tree_lookup(const struct inode *);
281 extern void audit_put_chunk(struct audit_chunk *);
282 extern int audit_tree_match(struct audit_chunk *, struct audit_tree *);
283 extern int audit_make_tree(struct audit_krule *, char *, u32);
284 extern int audit_add_tree_rule(struct audit_krule *);
285 extern int audit_remove_tree_rule(struct audit_krule *);
286 extern void audit_trim_trees(void);
287 extern int audit_tag_tree(char *old, char *new);
288 extern const char *audit_tree_path(struct audit_tree *);
289 extern void audit_put_tree(struct audit_tree *);
290 extern void audit_kill_trees(struct list_head *);
291 #else
292 #define audit_remove_tree_rule(rule) BUG()
293 #define audit_add_tree_rule(rule) -EINVAL
294 #define audit_make_tree(rule, str, op) -EINVAL
295 #define audit_trim_trees() (void)0
296 #define audit_put_tree(tree) (void)0
297 #define audit_tag_tree(old, new) -EINVAL
298 #define audit_tree_path(rule) ""	/* never called */
299 #define audit_kill_trees(list) BUG()
300 #endif
301 
302 extern char *audit_unpack_string(void **, size_t *, size_t);
303 
304 extern pid_t audit_sig_pid;
305 extern kuid_t audit_sig_uid;
306 extern u32 audit_sig_sid;
307 
308 #ifdef CONFIG_AUDITSYSCALL
309 extern int __audit_signal_info(int sig, struct task_struct *t);
audit_signal_info(int sig,struct task_struct * t)310 static inline int audit_signal_info(int sig, struct task_struct *t)
311 {
312 	if (unlikely((audit_pid && t->tgid == audit_pid) ||
313 		     (audit_signals && !audit_dummy_context())))
314 		return __audit_signal_info(sig, t);
315 	return 0;
316 }
317 extern void audit_filter_inodes(struct task_struct *, struct audit_context *);
318 extern struct list_head *audit_killed_trees(void);
319 #else
320 #define audit_signal_info(s,t) AUDIT_DISABLED
321 #define audit_filter_inodes(t,c) AUDIT_DISABLED
322 #endif
323 
324 extern struct mutex audit_cmd_mutex;
325